BB cream- help to brighten and protect the skin. They usually have a higher SPF than foundation products. They have a slight tint to them and most brands will work better for normal to oily skin types.
Use these products if you have normal to oily skin, want to protect your skin from the sun/pollution. Want a light coverage on your skin.
CC cream- these are colour correctors. They help to address specific skin issues for a brighter,healthier looking skin. They work on improving the tone of the skin. Most work well with redness and have an SPF.
Use these products if your skin has redness, dull or is tired looking. Can be used under your foundation.
Primers- These come in many different types,textures and for many different purposes. The general idea of these is to smooth and prime the skin ready for a flawless foundation application.
If you want to use this product you will have to decide what your main concern is first!
Check out my blog Primers A Quick Guide for more information.